Patent Application
20070288154
Turning now to the drawings wherein like numbers refer to like structures, and particularly to
Engine 10 includes an engine control module (ECM) or controller representatively indicated by reference numeral 14. ECM 14 communicates with various engine sensors and actuators via associated cabling or wires, indicated generally by reference numeral 18, to control the engine. In addition, ECM 14 communicates with the engine operator using associated lights, switches, displays, and the like as illustrated in greater detail in
Referring now to
Actuators 36 include various engine components that are operated via associated control signals from controller 32. As indicated in
Sensors 34 and actuators 36 may be used to communicate status and control information to an engine operator via a console 48. Console 48 may include various switches 50 and 54 in addition to indicators 52. Console 48 is preferably positioned in close proximity to the engine operator, such as in the cab of a vehicle. Indicators 52 may include any of a number of audio and visual indicators such as lights, displays, buzzers, alarms, and the like. Preferably, one or more switches, such as switch 50 and switch 54, are used to request a particular operating mode, such as cruise control or PTO mode, for example.
In one embodiment, controller 32 includes a programmed microprocessing unit 70 in communication with the various sensors 34, 38, 40, 44, 62 and actuators 36 via input/output port 72. As is well known by those of skill in the art, input/output ports 72 provide an interface in terms of processing circuitry to condition the signals, protect controller 32, and provide appropriate signal levels depending on the particular input or output device. Processor 70 communicates with input/output ports 72 using a conventional data/address bus arrangement 74. Likewise, processor 70 communicates with various types of computer-readable storage media 76 which may include a non-volatile RAM (NVRAM) 78, a read-only memory (ROM) 80, and a random-access memory (RAM) 82. The various types of computer-readable storage media 76 provide short-term and long-term storage of data used by controller 32 to control the engine. Computer-readable storage media 76 may be implemented by any of a number of known physical devices capable of storing data representing instructions executable by microprocessor 70. Such devices may include PROM, EPROM, BEPROM, flash memory, and the like in addition to various magnetic, optical, and combination media capable of temporary and/or permanent data storage.
Computer-readable storage media 76 include data representing program instructions (software), calibrations, operating variables, and the like used in conjunction with associated hardware to control the various systems and subsystems of the engine and/or vehicle. The engine/vehicle control logic is implemented via controller 32 based on the data stored in computer-readable storage media 76 in addition to various other electric and electronic circuits (hardware).
In one embodiment of the present invention, controller 32 includes control logic to reduce unnecessary engine idling and conform the engine idling to the regulations required by the geographical location within which the engine is operating. It is contemplated that the controller 32 has data tables that are loaded with idling requirements of any geographical location. Control logic implemented by controller 32 monitors operating conditions of the engine and/or vehicle to determine that the vehicle is stationary. Likewise, controller 32 determines that the engine has been idling for a period of time by initiating a timer/counter to track the idling time. Determining that the engine is idling may be performed in a number of manners. For example, an engine idling condition may be determined based on position of an accelerator pedal, or the engine speed being below a predetermined idle speed (which may vary according to the engine or ambient temperature). Controller 32 then determines the engine load to detect whether the engine is being used, for example, to drive an auxiliary device. However, those having ordinary skill in the art will appreciate that the present invention is not limited to this operational condition.
Controller 32 then will receive information relative to the geographical location of the engine and will automatically stop the engine when the idling time exceeds a programmable limit and the engine load is less than a second programmable limit indicating the engine is not being used to drive an auxiliary device. Of course, depending upon the particular application, one or more load thresholds may be utilized to determine whether the engine is being used to drive an auxiliary device.
As used throughout the description of the invention, a selectable or programmable limit or threshold may also be selected by any of a number of individuals via a programming device, such as device 66 selectively connected via an appropriate plug or connector 68 to controller 32. Rather than being primarily controlled by software, the selectable or programmable limit may also be provided by an appropriate hardware circuit having various switches, dials, and the like. Of course, the selectable or programmable limit may also be changed using a combination of software and hardware without departing from the spirit of the present invention.
As described above, compression ignition engines having an idle shut down feature have been employed to reduce the amount of unnecessary idling of the engine. Typically, the systems automatically stop the engine after a predetermined or selectable idling time to conserve fuel. However, many engine operators attempt to defeat this feature to keep the engine idling for an indefinite period of time. For example, a driver may want to keep the engine idling to avoid difficulty in restarting the engine after stopping at a rest area. As such, the driver “tricks” the engine by selecting an operating mode that does not activate or trigger the idle shut down feature. One example where an operator may attempt to override idle shut down occurs where an operator selects the PTO mode of operation even though the engine is not being used to drive an auxiliary load. Typically, operation in the PTO mode automatically disables the idle shut down feature of the engine. By selecting an operating mode (PTO) that is inconsistent with the current operating conditions (no auxiliary device connected), the operator has defeated the idle shut down feature. According to the present invention, controller 32 determines whether the requested operating mode is inconsistent with the current operating conditions to determine whether to automatically stop the engine. In one embodiment, engine controller 32 provides a warning to the operator to indicate that the engine will be automatically stopped. The driver is afforded a limited number of opportunities to override the automatic engine shut down. Preferably, controller 32 determines whether the requested operating mode is consistent (or inconsistent) with the current operating conditions by comparing the engine load to a selectable or programmable load threshold. If the engine is being used to drive an auxiliary device, the engine will be loaded accordingly. As such, controller 32 will override the automatic shut down feature to keep the engine running. However, if the engine operating conditions indicate that the selected mode of operation is inconsistent or inappropriate, the idle shutdown feature will be activated and the engine will be automatically stopped after the associated criteria have been satisfied, i.e. idle time, number of overrides, etc.
Turning to
If the engine idling time is greater than the allowed idle time, step 106 is shutting down the engine. The idle shut down strategy of the present invention may be overridden by merely depressing the accelerator pedal.
Those skilled in the art will understand that the terms used in this description are illustrative and are not intended to be limiting in any way to the scope of the invention. In addition, various modifications will become apparent to those skilled in the art without departing form the scope and spirit of the invention.
